After Pearl Harbor, Franklin Roosevelt called on the country to become an arsenal of democracy, and Chicago answered with factories that never stopped running. This film traces how the city retooled its stockyards, steel mills, and manufacturing plants to turn out tanks, bombers, and munitions, with women and teenagers filling jobs left by men shipped overseas. Personal reminiscences from people who lived through the mobilization sit alongside declassified government footage, period newsreels, posters, and stills documenting the shift from peacetime industry to total war production. A key thread follows the political partnership between Roosevelt and Chicago's Democratic mayor Ed Kelly, showing how federal contracts and local machine politics reinforced each other to keep output high. The film treats Chicago as a case study in the home front rather than a footnote to the battlefield story, arguing that the war was won as much in the city's plants and rail yards as on any front line overseas.